private void ProcessExif(byte[] section)
{
int idx = 6;
if (section[idx++] != 0 ||
section[idx++] != 0)
{
// "Exif" is not followed by 2 null bytes.
return;
}
if (section[idx] == 'I' && section[idx + 1] == 'I')
{
// intel order
littleEndian = true;
}
else
{
if (section[idx] == 'M' && section[idx + 1] == 'M')
{
littleEndian = false;
}
else
{
// unknown order...
return;
}
}
idx += 2;
int a = ExifIO.ReadUShort(section, idx, littleEndian);
idx += 2;
if (a != 0x002A)
{
// bad start...
return;
}
a = ExifIO.ReadInt(section, idx, littleEndian);
idx += 4;
if (a < 8 || a > 16)
{
if (a < 16 || a > section.Length - 16)
{
// invalid offset
return;
}
}
ProcessExifDir(section, a + 8, 8, section.Length - 8, 0, ExifIFD.Exif);
}
private void ProcessExif(byte[] section, long sectionStart)
{
int num1 = 6;
byte[] numArray1 = section;
int index1 = num1;
int num2 = 1;
int num3 = index1 + num2;
if ((int)numArray1[index1] != 0)
{
return;
}
byte[] numArray2 = section;
int index2 = num3;
int num4 = 1;
int index3 = index2 + num4;
if ((int)numArray2[index2] != 0)
{
return;
}
if ((int)section[index3] == 73 && (int)section[index3 + 1] == 73)
{
this.littleEndian = true;
}
else
{
if ((int)section[index3] != 77 || (int)section[index3 + 1] != 77)
{
return;
}
this.littleEndian = false;
}
this.info.LittleEndian = this.littleEndian;
int offset1 = index3 + 2;
int num5 = (int)ExifIO.ReadUShort(section, offset1, this.littleEndian);
int offset2 = offset1 + 2;
if (num5 != 42)
{
return;
}
int num6 = ExifIO.ReadInt(section, offset2, this.littleEndian);
int num7 = offset2 + 4;
if ((num6 < 8 || num6 > 16) && (num6 < 16 || num6 > section.Length - 16))
{
return;
}
this.ProcessExifDir(section, num6 + 8, 8, section.Length - 8, 0, ExifIFD.Exif, sectionStart);
}
public ExifTag(byte[] section, int sectionOffset, int offsetBase, int length, bool littleEndian)
{
this.IsValid = false;
this.Tag = ExifIO.ReadUShort(section, sectionOffset, littleEndian);
int format = ExifIO.ReadUShort(section, sectionOffset + 2, littleEndian);
if (format < 1 || format > 12)
{
return;
}
this.Format = (ExifTagFormat)format;
this.Components = ExifIO.ReadInt(section, sectionOffset + 4, littleEndian);
if (this.Components > 0x10000)
{
return;
}
this.LittleEndian = littleEndian;
int byteCount = this.Components * BytesPerFormat[format];
int valueOffset = 0;
if (byteCount > 4)
{
int offsetVal = ExifIO.ReadInt(section, sectionOffset + 8, littleEndian);
if (offsetVal + byteCount > length)
{
// bad offset...
return;
}
valueOffset = offsetBase + offsetVal;
}
else
{
valueOffset = sectionOffset + 8;
}
this.Data = new byte[byteCount];
Array.Copy(section, valueOffset, this.Data, 0, byteCount);
this.IsValid = true;
}
public ExifTag(byte[] section, int sectionOffset, int offsetBase, int length, bool littleEndian)
{
this.IsValid = false;
this.Tag = (int)ExifIO.ReadUShort(section, sectionOffset, littleEndian);
int index = (int)ExifIO.ReadUShort(section, sectionOffset + 2, littleEndian);
if (index < 1 || index > 12)
{
return;
}
this.Format = (ExifTagFormat)index;
this.Components = ExifIO.ReadInt(section, sectionOffset + 4, littleEndian);
if (this.Components > 65536)
{
return;
}
this.LittleEndian = littleEndian;
int length1 = this.Components * ExifTag.BytesPerFormat[index];
int sourceIndex;
if (length1 > 4)
{
int num = ExifIO.ReadInt(section, sectionOffset + 8, littleEndian);
if (num + length1 > length)
{
return;
}
sourceIndex = offsetBase + num;
}
else
{
sourceIndex = sectionOffset + 8;
}
this.Data = new byte[length1];
this.ValueOffset = (long)sourceIndex;
Array.Copy((Array)section, sourceIndex, (Array)this.Data, 0, length1);
this.IsValid = true;
}
private int ReadInt(int offset)
{
return(ExifIO.ReadInt(Data, offset, LittleEndian));
}
private void ProcessExifDir(byte[] section, int offsetDir, int offsetBase, int length, int depth, ExifIFD ifd)
{
if (depth > 4)
{
// corrupted Exif header...
return;
}
ushort numEntries = ExifIO.ReadUShort(section, offsetDir, littleEndian);
if (offsetDir + 2 + 12 * numEntries >= offsetDir + length)
{
// too long
return;
}
int offset = 0;
for (int de = 0; de < numEntries; ++de)
{
offset = DirOffset(offsetDir, de);
ExifTag exifTag = new ExifTag(section, offset, offsetBase, length, littleEndian);
if (!exifTag.IsValid)
{
continue;
}
switch (exifTag.Tag)
{
case (int)ExifIFD.Exif:
{
int dirStart = offsetBase + exifTag.GetInt(0);
if (dirStart <= offsetBase + length)
{
ProcessExifDir(section, dirStart, offsetBase, length, depth + 1, ExifIFD.Exif);
}
} break;
case (int)ExifIFD.Gps:
{
int dirStart = offsetBase + exifTag.GetInt(0);
if (dirStart <= offsetBase + length)
{
ProcessExifDir(section, dirStart, offsetBase, length, depth + 1, ExifIFD.Gps);
}
} break;
default:
{
exifTag.Populate(info, ifd);
} break;
}
}
// final link defined?
offset = DirOffset(offsetDir, numEntries) + 4;
if (offset <= offsetBase + length)
{
offset = ExifIO.ReadInt(section, offsetDir + 2 + 12 * numEntries, littleEndian);
if (offset > 0)
{
int subDirStart = offsetBase + offset;
if (subDirStart <= offsetBase + length && subDirStart >= offsetBase)
{
ProcessExifDir(section, subDirStart, offsetBase, length, depth + 1, ifd);
}
}
}
if (info.ThumbnailData == null && info.ThumbnailOffset > 0 && info.ThumbnailSize > 0)
{
// store it.
info.ThumbnailData = new byte[info.ThumbnailSize];
Array.Copy(section, offsetBase + info.ThumbnailOffset, info.ThumbnailData, 0, info.ThumbnailSize);
}
}
private void ProcessExifDir(byte[] section, int offsetDir, int offsetBase, int length, int depth, ExifIFD ifd, long sectionStart)
{
if (depth > 4)
{
return;
}
ushort num1 = ExifIO.ReadUShort(section, offsetDir, this.littleEndian);
if (offsetDir + 2 + 12 * (int)num1 >= offsetDir + length)
{
return;
}
for (int num2 = 0; num2 < (int)num1; ++num2)
{
int sectionOffset = this.DirOffset(offsetDir, num2);
ExifTag exifTag = new ExifTag(section, sectionOffset, offsetBase, length, this.littleEndian);
if (exifTag.IsValid)
{
switch (exifTag.Tag)
{
case 34665:
int offsetDir1 = offsetBase + exifTag.GetInt(0);
if (offsetDir1 <= offsetBase + length)
{
this.ProcessExifDir(section, offsetDir1, offsetBase, length, depth + 1, ExifIFD.Exif, sectionStart);
continue;
}
continue;
case 34853:
int offsetDir2 = offsetBase + exifTag.GetInt(0);
if (offsetDir2 <= offsetBase + length)
{
this.ProcessExifDir(section, offsetDir2, offsetBase, length, depth + 1, ExifIFD.Gps, sectionStart);
continue;
}
continue;
default:
exifTag.Populate(this.info, ifd, sectionStart);
continue;
}
}
}
if (this.DirOffset(offsetDir, (int)num1) + 4 <= offsetBase + length)
{
int num2 = ExifIO.ReadInt(section, offsetDir + 2 + 12 * (int)num1, this.littleEndian);
if (num2 > 0)
{
int offsetDir1 = offsetBase + num2;
if (offsetDir1 <= offsetBase + length && offsetDir1 >= offsetBase)
{
this.ProcessExifDir(section, offsetDir1, offsetBase, length, depth + 1, ifd, sectionStart);
}
}
}
if (this.info.ThumbnailData != null || this.info.ThumbnailOffset <= 0 || this.info.ThumbnailSize <= 0)
{
return;
}
this.info.ThumbnailData = new byte[this.info.ThumbnailSize];
Array.Copy((Array)section, offsetBase + this.info.ThumbnailOffset, (Array)this.info.ThumbnailData, 0, this.info.ThumbnailSize);
}